Preparations for Bob v4 release

* Remove all outdated files
* Port to new CI (closes #25, closes #44)
* Activate caching (closes #43)
2 jobs for preps-for-release in 24 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Build
failed #122636
docker
build_linux

00:00:17

failed #122637
macosx
build_macosx

00:00:12

 
Name Stage Failure
failed
build_macosx Build There is an unknown failure, please try again
(14:41:14) $ chmod 755 _ci/pypi.sh
(14:41:14)
$ curl --location --silent --show-error --output _ci/channel_support.py https://gitlab.idiap.ch/bob/bob.admin/raw/master/gitlab/channel_support.py
(14:41:15)
$ chmod 755 _ci/channel_support.py
$ ./_ci/before_build.sh
(14:41:15.190)
Error: ./version.txt does not exist - cannot figure out version number
Running after script...
$ ./_ci/after_build.sh
(14:41:15.237)
Error: ./version.txt does not exist - cannot figure out version number
ERROR: Job failed: exit status 1
failed
build_linux Build There is an unknown failure, please try again
(13:40:54) $ chmod 755 _ci/pypi.sh
(13:40:54)
$ curl --location --silent --show-error --output _ci/channel_support.py https://gitlab.idiap.ch/bob/bob.admin/raw/master/gitlab/channel_support.py
(13:40:54)
$ chmod 755 _ci/channel_support.py
$ ./_ci/before_build.sh
(13:40:54.749)
Error: ./version.txt does not exist - cannot figure out version number
Running after script...
$ ./_ci/after_build.sh
(13:40:56.616)
Error: ./version.txt does not exist - cannot figure out version number
ERROR: Job failed: exit code 1